|Think about Loose Coupling|
pj said in the OP that top 100 free apps earn $15,000/mo but have you seen the top 100? They're all games, music/videos/images, social networking, search, weather, maps, games --- nothing programming related, so there goes that incentive :)
Yes, I know (sigh), it's all a bit depressing. There are however sites out there that make money from more serious applications. To take an example, there are a number of free medical apps out there - have you seen the one that takes your pulse with an iPhone by putting your thumb over the camera? Totally amazing, as a physicist I don't know how they do it. Anyhow the rich and status conscious doctors where I live (in Sao Paulo), are generally comming to conclusion that these 'freebies' look unprofessional and are paying for more commercial grade applications.
Another is a site I use which looks like a normal journalistic IT site, but is in fact an IT trends research company, which languages, which hardware, which insourcing, which outsourcing etc. If you buy the commerical subscription, you get access to all the research results. They are on-track to make a substantial amount of money this year.
So there are more serious applications out there. Maybe PerlMonks will not be in the top 100, but that's cool too.
I value the free, unstinting support that it has given me over the last two or so years that I have used it. I couldn't have achieved what I've done without it. But, to protect my investment in Perl, I also want to attract more and younger programmers to the profession - like pj (I recall he says he's young somewhere). I want these guys to be excited and motivated by what we have to offer.
Anyhow, live long and prosper Anon,